Marc et al. reported that diazepam increased plasma corticosterone level and Dasgupta et al. suggested that chlordiazepoxide(CDP) supressed the adrenal response to ACTH. In this paper, the influence of CDP on the changes of blood sugar and plasma corticosterone level induced by ACTH and picrotoxin were investigated in male mice. The results obtained were summarized as follows; 1) The blood sugar and plasma corticosterone level were increased by CDP, ACTH, and picrotoxin, respectively. 2) The hyperglycemia induced by ACTH and picrotoxin were not affected by the CDP pretreatment. 3) The increase of plasma corticosterone level induced by ACTH was inhibited by the CDP pretreatment. 4) The increase of plasma corticosterone level appeared 30 minutes after picrotoxin injection was slightly enhanced, but the level of 120 minutes after picrotoxin injection was significantly inhibited by the CDP pretreatment.